“Due to various anti-drug lectures he was exposed to at school, my 13-year-old son believes that marijuana is not on illegal, but also is very bad for you. He said it is poison.

My state has recently legalized marijuana and I am at a loss about how to explain to him that pot is no longer “that bad,” as people partake of it in a responsible manner going forward. Any suggestions?”

Your honest answer impressed me in the following ways.

“Marijuana isn’t poison, unless it was sprayed with a poisonous chemical before being harvested. The marijuana sold to adults in the states where it is now legal has been carefully cultivated and harvested.”

True.

Marijuana, by itself, isn’t deadly. There have been no deaths directly attributed to the consumption of cannabis. Back in the 1970s, there was concern about the spraying of marijuana with Paraquat. But now, particularly in states where marijuana is legally controlled and regulated, crops and processing is safer than ever before.

You continue, “Its use is not encouraged among teenagers, however, because research has shown it can impair brain development among young people.”

Yes and maybe.

It is widely agreed that for teenagers, abstinence is the safest choice, because marijuana, like other psychoactive substances, changes the way a person thinks, feels, and perceives his or her surroundings—getting in the way of learning and growing. The science about actual brain development, however, is in its infancy, and not yet definitive.

You then advise Mom in Colorado, “Stress to your son that like alcohol, marijuana can slow reaction time and impair judgment and memory, which is why it’s illegal for minors to use it.”

True. Both alcohol and marijuana can slow reaction time and can impair judgment and memory. Alcohol and marijuana are also illegal for minors because like many other “adult” activities, understanding the importance of context, moderation, and responsibility requires maturity. That’s why it’s so important to delay.

And finally, “Whether it will become legal across the nation is still an open question. If it’s abused the way that alcohol sometimes is, smoking weed may also be harmful because, like any smoke, it poses a risk to the lungs.”

True. Although the movement to legalize marijuana has gained momentum, with a majority of Americans now supporting a regulated system, ending prohibition will be a slow process. And yes, if over-used, any kind of smoking can have an impact on the pulmonary system. This is the reason that adult users are eschewing smoking in favor of less harmful methods of ingestion.

Like Mom in Colorado, and so many other parents, I struggled with the drug issue when my own children were teenagers. Here is the letter (published then in the San Francisco Chronicle) I wrote to my then-14-year-old-son, and his response to me—eight years later.

Marsha Rosenbaum is director emerita of the Drug Policy Alliance's San Francisco office and the founder of the Safety First project at the Drug Policy Alliance. Her booklet, written for parents, Safety First: A Reality-Based Approach to Teens and Drugs is available at www.safety1st.org.